1. Field of the Invention
The present invention relates to an engine starter which is used in starting automotive engines, particularly to an engine starter equipped with a drive shaft which rotates upon receipt of driving force of an electric motor and, moves in the axial direction thereof.
2. Description of Related Art
There have been engine starters equipped with drive shafts which move in the axial direction thereof while rotating due to the driving force of an electric motor, an example of which being that laid open in the Patent Application Laid-Open No. 63-90665. In this and other engine starters of the prior art, a pinion which is engaged or disengaged with a ring gear of the engine to be started is fitted, by means of a straight spline or the like, on the periphery of the front end of the drive shaft which moves axially while rotating. Also installed at the front end of the drive shaft which protrudes beyond the end face of the pinion is a stopper which prevents the pinion from dropping off.
The engine starter laid open in the publication mentioned above is a coaxial type engine starter, and is equipped with an electromagnetic switch which switches on the power to the electric motor disposed at the rear of the electric motor. Therefore, although the entire configuration is a thin cylinder and the construction is simple, its total length is greater than that of a 2-axis type engine starter.
In order to make effective use of the space in the engine room of an automobile or to reduce the weight of an automobile, automotive parts are required to become smaller in size. Engine starters, either coaxial or 2-axis type, are strongly required to become smaller, particularly in length.